POV-Ray : Newsgroups : povray.beta-test : Isosurface behaving differently in beta 3 Server Time
12 Nov 2024 19:56:14 EST (-0500)
  Isosurface behaving differently in beta 3 (Message 1 to 2 of 2)  
From: Mike Williams
Subject: Isosurface behaving differently in beta 3
Date: 23 Sep 2001 14:49:42
Message: <0w3GBAA04ir7Ewou@econym.demon.co.uk>
One of the example isosurfaces in my tutorial renders very differently
in beta 3 than it did in betas 1 and 2. In the previous versions, and in
MegaPOV it produces the expected cylinder (it's a sphere scaled
infinitely in the x direction by substituting "0"  for "x"). In 3.5b3
the surface does not appear.

I've tried adding "evaluate 1,10,0.99" and it still comes out blank, and
suggests that the max_gradient should be 0.000.

POV 3.5b3, AMD K6-2 500, W98se, 128Mb

=================================
camera { location  <0, 0, -4> look_at <0, 0, 0>}

light_source {<-100,200,-100> colour rgb 1}

#declare  S = function {x^2 + y^2 + z^2 - 1}
                     
isosurface {
  function { S(0,y,z) }
        max_gradient 4
        contained_by{sphere{0,2}}
        pigment {rgb 1}
}
=================================

If I change it to "function { S(x*0,y,z) }", which is obviously an
identical function, it renders correctly (and very much quicker). Weird.
S(x,0,z) and S(x,y,0) behave correctly, it's just S(0,y,z) that goes
wrong.

It looks like the details of the function aren't important, it's the
"function Foo(0,..,..)" that provokes the strange behaviour.

-- 
Mike Williams
Gentleman of Leisure


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From: Thorsten Froehlich
Subject: Re: Isosurface behaving differently in beta 3
Date: 23 Sep 2001 15:15:07
Message: <3bae34bb$1@news.povray.org>
In article <0w3### [at] econymdemoncouk> , Mike Williams 
<mik### [at] nospamplease>  wrote:

> It looks like the details of the function aren't important, it's the
> "function Foo(0,..,..)" that provokes the strange behaviour.

Yes, see

From: "Elias Pschernig" <eli### [at] aonat>
Newsgroups: povray.beta-test
Subject: min/max stop working in functions?
Date: Sun, 23 Sep 2001 14:47:40 +0200
Message-ID: <3bade3d7@news.povray.org>

and my replies.


____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

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